Tortoises are amazing reptiles, they have extremely long history. Although it is still a myth who was tortoises’ ancestors, some say it’s the Proganochelys- a land turtle (evolved from underwater creature) and some say it’s the Pareiasaur because of the bone structure, others proposed it was Odontochelys semitestacea. However, because Odontochelys semitestacea was the oldest animal of all, it was predicted that turtles and tortoises came from this ancestor. Odontochelys semitestacea is a half sea lizard, half turtle, it has primitive features such as teeth and a long tail. As mentioned, this ancestor is half of a turtle because it owns the lower portion of the shell, the plastron, while the dorsal part consists of broadened ribs and not a carapace.
Archaeologists measure the average length to be 40 cm long (very close to the modern animal’s size). It belonged to the late Triassic period 220 MA , where the reptiles ruled the world. Living under water, its diet was mainly small creatures. It discovery helped humans to reveal the evolution of the tortoise shell and why there are two branches- turtles and tortoises.
Ruler
(Odontochelys semitestacea's length will be 8 or 7.5 times of the ruler given)
Scientific Classification:
Kingdom:
Animalia
Phylum:
Chordata
Class:
Sauropsida
Subclass:
Anapsida
Order:
Testudines
Suborder:
Proganochelydia
Family:
Odontochelyidae
Genus:
Odontochelys
Species:
O. semitestacea
Analysis of essential features for survival
In the Triassic period, the climate was different from the present. At that time, the Pangaea hasn’t yet split, affecting the whole big continent as most areas are near the equator. As a result, it has hot summers and cold winter, sometimes accompanied by violent monsoons. Odontochelys semitestacea are located in the inland ocean because the temperature is much cooler.
As a fully capable swimmer, it seldom needs to swim up to the surface for oxygen. Once It does swim up for oxygen, it could take it another 50 minutes before another breathe. Underwater where they live, they are surrounded by new types of species. There were corals,ammonites and fish fauna which recovered from the Permian extinction. Furthermore, they were accompanied by new marine reptiles such as the Sauropterygia, placodonts, and the first plesiosaurs; the first of the lizard like Thalattosauria, and ichthyosaurs.
Predicted Odontochelys semitestace’s marine life
The image is an example of Odontochelys semitestacea's marine life. They probably feed on fishes like the Arandaspis , and other small water creatures near the coral reefs. They also like to swim near the sea bed to scavenge for traces of meat left over by other predators. Furthermore, they will often hide near or under coral reefs to protect themselves from bigger predators.
Triassic period was often accompanied by sudden volcanic eruption because the continents are always unstable. Being only 40 cm long, Odontochelys semitestacea has an advantage because of its small size. It could escape from the lava and swim fast enough away from the boiling sea water. Unlike turtles or tortoises, they don’t have peaceful environments because their home was roamed by 100 times bigger predators and unstable sea bed.
Structural Adaptations:
Fossil scute of the Odontochelys semitestacea
1) Odontochelys semitestacea are only half turtles because they have the lower part of the shell, and their other half are lizards. All reptiles have very rough skin- scales. There are different types of scales such as lizards, snake, and scutes which are commonly seen on crocodiles and tortoises skin.
This ancient ancestor’s skin is categorised as scutes. Since their skin are specially built and are more heavier, it is harder to penetrate. Different from fish and other animals, the outer layer of the skin is made out of thick stratum corneum. The corneum cells then arranges into horny scales that cover the reptiles entire body, whereas the inner layer are connective tissues. The environmental pressure to cause this adaptation might be because they don’t want predators' sharp teeth to hurt them when hunting, therefore their skin are made out of hard, horny scales.
Odontochelys semitestacea webbed feet
2) This species limbs are not flippers like turtles, or elephant legs like tortoises. They are webbed like Polar Bear, Black Swan and Platypus. Their legs are specially designed so that they can swim freely in the ocean and walk on land. Webbed feet for this ancestor animal can be used for swimming in the ocean and digging for food near the sea bed. Odontochelys semitestacea are such good swimmers because of their webbed feet, they are just like flippers. It is very important to this animal because it can assist them to escape from predators. By paddling their legs back and forth, they could easily, effortlessly and swiftly swim metres away from their enemies. One of the reasons as to why they would have webbed feet is because it can help them swim better, and it doesn’t restrict how they find food. Animals like turtles who have ‘flippers’ are quite restricted as to what they can do other then swimming, and other actions like digging would be tough for them. However, webbed feet does not has this restriction. Odontochelys semitestacea can dig easily with the claws and swim in the ocean.
Behavioural adaptations:
1) To find food, the Odontochelys semitestacea will dive down to the sea bed and use their fore legs to scavenge for food. It is an advantage for them because the left over meat that had already been consumed by other larger predators has torn it into small pieces; therefore they would not need to use their tiny teeth to rip big parts of meat. They might have discovered this behaviour while hiding near the coral reefs. If the ancestor does not feel full, it will continue to scavenge for little creatures near the sea bed or reefs. Their hands are very similar to humans, while Homo sapiens use theirs to hold and eat food, they will use their claws to dig under small stones. Furthermore, they would also use the tip of their snout to remove stones or anything blocking their food. They will first dig open a hole using their fore limbs, then they will use their muzzle to wriggle away the sand, and when the whole is big enough, it will swim through and consume the prey. With the help of their body parts like legs, muzzle and incredible lungs, they can swim in the sea for 50 minutes before grasping for another mouth of air.
School of fish
2)The descendants of this ancestor like to be alone when hunting, or swimming. It is not until mating season when they come together to reproduce. Yet, Odontochelys semitestacea hunt in groups for it seems to be easier to have a meal. Their pack number will be around twelve to fifteen; such large group of ancestors could easily feed themselves with a good strategy.
a) They will swim around the sea to find schools of small fish
b) Once they find them, they will surround the school.
c) Some will start to swim straight to wards the fish to have its meal, while others sustain the schools of fish as a pool and wait for its turn.
d) They will stop when every member of the group is full.
e) The next day, steps 1 to 4 are repeated again.
Physiological Adaptation:
Blood Cells
The blood in their bodies is very crucial to their life. First of all, they are ectothermic meaning cold blooded animals, therefore they have a slower metabolism rate allowing them to stay under the sea for a longer period of time after every grasping of air. Secondly, if they decide to dive deep for a long period of time, their blood will be blocked from tissues that allow low blood supplies. Thirdly, because they have a higher concentration of blood, the haemoglobins can retain more oxygen from the surface which allows them to swim and dive deeper. Gradually, when these animals become 100% part of the marine life, they will need to this adaptation to help them fully mature and evolve to sea creatures.
Extinction Pressure:
One of the possibilties that lead to extinction
The Triassic period extinction affected marine life the most. Nearly every marine species extinct and only some like the ichthyosaurs and plesiosaurs were managed to survive. The reason as to why Triassic period extinction is still unknown. Some scientists said it was because of a massive volcanic eruption (the one who broke the super- continent). The energy that broke the Pangaea might have boiled up the ocean water as the lava continuously flowed out, causing marine lives to vanish. Others say it is either global cooling freezing the marine animals including Odontochelys semitestacea to death or the impact of a great meteor. Any how, all the given possibilties could drive Odontochelys semitestacea to extinction, leaving little traces such as fossil bones for scientists, archaeologists to reveal the myth.
Tortoises are amazing reptiles, they have extremely long history. Although it is still a myth who was tortoises’ ancestors, some say it’s the Proganochelys- a land turtle (evolved from underwater creature) and some say it’s the Pareiasaur because of the bone structure, others proposed it was Odontochelys semitestacea. However, because Odontochelys semitestacea was the oldest animal of all, it was predicted that turtles and tortoises came from this ancestor.
Odontochelys semitestacea is a half sea lizard, half turtle, it has primitive features such as teeth and a long tail. As mentioned, this ancestor is half of a turtle because it owns the lower portion of the shell, the plastron, while the dorsal part consists of broadened ribs and not a carapace.
Archaeologists measure the average length to be 40 cm long (very close to the modern animal’s size). It belonged to the late Triassic period 220 MA , where the reptiles ruled the world. Living under water, its diet was mainly small creatures. It discovery helped humans to reveal the evolution of the tortoise shell and why there are two branches- turtles and tortoises.
Scientific Classification:
In the Triassic period, the climate was different from the present. At that time, the Pangaea hasn’t yet split, affecting the whole big continent as most areas are near the equator. As a result, it has hot summers and cold winter, sometimes accompanied by violent monsoons. Odontochelys semitestacea are located in the inland ocean because the temperature is much cooler.
As a fully capable swimmer, it seldom needs to swim up to the surface for oxygen. Once It does swim up for oxygen, it could take it another 50 minutes before another breathe. Underwater where they live, they are surrounded by new types of species. There were corals,ammonites and fish fauna which recovered from the Permian extinction. Furthermore, they were accompanied by new marine reptiles such as the Sauropterygia, placodonts, and the first plesiosaurs; the first of the lizard like Thalattosauria, and ichthyosaurs.
, and other small water creatures near the coral reefs. They also like to swim near the sea bed to scavenge for traces of meat left over by other predators. Furthermore, they will often hide near or under coral reefs to protect themselves from bigger predators.
Triassic period was often accompanied by sudden volcanic eruption because the continents are always unstable. Being only 40 cm long, Odontochelys semitestacea has an advantage because of its small size. It could escape from the lava and swim fast enough away from the boiling sea water. Unlike turtles or tortoises, they don’t have peaceful environments because their home was roamed by 100 times bigger predators and unstable sea bed.
Structural Adaptations:
This ancient ancestor’s skin is categorised as scutes. Since their skin are specially built and are more heavier, it is harder to penetrate. Different from fish and other animals, the outer layer of the skin is made out of thick stratum corneum. The corneum cells then arranges into horny scales that cover the reptiles entire body, whereas the inner layer are connective tissues. The environmental pressure to cause this adaptation might be because they don’t want predators' sharp teeth to hurt them when hunting, therefore their skin are made out of hard, horny scales.
Behavioural adaptations:
1) To find food, the Odontochelys semitestacea will dive down to the sea bed and use their fore legs to scavenge for food. It is an advantage for them because the left over meat that had already been consumed by other larger predators has torn it into small pieces; therefore they would not need to use their tiny teeth to rip big parts of meat. They might have discovered this behaviour while hiding near the coral reefs. If the ancestor does not feel full, it will continue to scavenge for little creatures near the sea bed or reefs. Their hands are very similar to humans, while Homo sapiens use theirs to hold and eat food, they will use their claws to dig under small stones. Furthermore, they would also use the tip of their snout to remove stones or anything blocking their food. They will first dig open a hole using their fore limbs, then they will use their muzzle to wriggle away the sand, and when the whole is big enough, it will swim through and consume the prey. With the help of their body parts like legs, muzzle and incredible lungs, they can swim in the sea for 50 minutes before grasping for another mouth of air.
a) They will swim around the sea to find schools of small fish
b) Once they find them, they will surround the school.
c) Some will start to swim straight to wards the fish to have its meal, while others sustain the schools of fish as a pool and wait for its turn.
d) They will stop when every member of the group is full.
e) The next day, steps 1 to 4 are repeated again.
Physiological Adaptation:
The blood in their bodies is very crucial to their life. First of all, they are ectothermic meaning cold blooded animals, therefore they have a slower metabolism rate allowing them to stay under the sea for a longer period of time after every grasping of air. Secondly, if they decide to dive deep for a long period of time, their blood will be blocked from tissues that allow low blood supplies. Thirdly, because they have a higher concentration of blood, the haemoglobins can retain more oxygen from the surface which allows them to swim and dive deeper. Gradually, when these animals become 100% part of the marine life, they will need to this adaptation to help them fully mature and evolve to sea creatures.
Extinction Pressure:
The Triassic period extinction affected marine life the most. Nearly every marine species extinct and only some like the ichthyosaurs and plesiosaurs were managed to survive. The reason as to why Triassic period extinction is still unknown. Some scientists said it was because of a massive volcanic eruption (the one who broke the super- continent). The energy that broke the Pangaea might have boiled up the ocean water as the lava continuously flowed out, causing marine lives to vanish. Others say it is either global cooling freezing the marine animals including Odontochelys semitestacea to death or the impact of a great meteor. Any how, all the given possibilties could drive Odontochelys semitestacea to extinction, leaving little traces such as fossil bones for scientists, archaeologists to reveal the myth.
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